docs: move Automatic Rejection section to end; note GitHub URL preference

Positive criteria (Quality Requirements, Acceptance Criteria, Entry
Format) now appear before the rejection list, reducing friction for
contributors reading top-to-bottom. Adds a note that GitHub URLs are
preferred because awesome-python.com ranks entries by GitHub stars.

Co-Authored-By: Claude <noreply@anthropic.com>

CONTRIBUTING.md

@@ -1,18 +1,5 @@
 # Contributing
 
-## Automatic Rejection
-
-PRs will be **closed** if:
-
-- Adding multiple projects in one PR
-- Duplicate of existing entry or recently-closed PR
-- Empty or placeholder PR descriptions
-- Placed under an inappropriate category
-- Project is archived or abandoned (no commits in 12+ months)
-- No documentation or unclear use case
-- Less than 100 GitHub stars without Hidden Gem justification
-- Repository less than 3 months old
-
 ## Quality Requirements
 
 All submissions must satisfy **ALL** of these:
@@ -52,6 +39,8 @@ Your submission must meet **ONE** of the following criteria:
 
 ## Entry Format Reference
 
+**Use GitHub repository URLs** whenever possible. Projects linked to a GitHub repo are ranked higher on [awesome-python.com](https://awesome-python.com/).
+
 ### Standard Entry
 
 ```markdown
@@ -101,3 +90,16 @@ PRs are reviewed by automated tools and maintainers:
 5. **Quality Check**: Meets acceptance criteria
 
 Search previous Pull Requests and Issues before submitting, as yours may be a duplicate.
+
+## Automatic Rejection
+
+PRs will be **closed** if:
+
+- Adding multiple projects in one PR
+- Duplicate of existing entry or recently-closed PR
+- Empty or placeholder PR descriptions
+- Placed under an inappropriate category
+- Project is archived or abandoned (no commits in 12+ months)
+- No documentation or unclear use case
+- Less than 100 GitHub stars without Hidden Gem justification
+- Repository less than 3 months old